Hour glass



FIG. 1 is a front, perspective view of an hour glass in accordance with the design of the present invention;

FIG. 2 is a left side, elevational view of the hour glass shown in FIG. 1, with the right side being a mirror image thereof;

FIG. 3 is a front, elevational view of the hour glass, shown in FIG. 1, with the rear view being a mirror image thereof; and,

FIG. 4 is a top, elevational view of the hour glass shown in FIG. 1, with the bottom view being identical thereto. 

The ornamental design for an hour glass, as shown and described. 